This invention relates to wave solder machines and more particularly to a wave solder machine for processing stuffed printed circuit (PC) boards of different and random sizes and shapes without the use of carriers for holding individual circuit boards.
A prior art method of producing circuit boards carrying electrical circuits is to assemble and process the boards on a progressive production line. Circuit boards having conductive traces thereon are located between a pair of tracks of a conveyor, which hold the boards by the edges thereof. As the tracks move the boards they are stuffed with components, fluxed, soldered, trimmed (the component leads thereon), and cleaned. In the wave solder machine in such a progressive line, the conveyor tracks hold the PC boards by edges thereof as the conveyor moves the undersides of the boards into contact with the solder wave. Such an assembly technique is only economically feasible when it is desirable to produce a large number of finished circuit boards having the same width.
In a prior-art wave solder machine for soldering component leads on circuit boards of size which occur in relatively small numbers, an operator must load the boards into carriers or racks having fixed outer dimensions and adjustable bars which hold the boards by edges thereof. Such a carrier is described in U.S. Pat. No. 3,930,644, issued Jan. 6, 1976 to E. V. Albert, Jr. The operator stuffs the racked circuit boards with components and then places the carriers on conveyor tracks of fixed dimensions which carry the undersides of the stuffed racked circuit boards into contact with the solder wave. The hand operations of loading circuit boards into and unloading them from such carriers involves considerable time and expense. The carriers themselves are also costly and require constant maintenance.
An object of this invention is the provision of an improved wave solder machine that is particularly adapted for economically and efficiently processing circuit boards of different sizes and shapes as well as large production runs of circuit boards of the same size.